{"id":"CVE-2021-1621","aliases":["EUVD-2021-7088","GHSA-7pgq-9248-43gw"],"status":"published","title":"Cisco IOS XE Software Interface Queue Wedge Denial of Service Vulnerability","description":"A vulnerability in the Layer 2 punt code of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a queue wedge on an interface that receives specific Layer 2 frames, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of certain Layer 2 frames. An attacker could exploit this vulnerability by sending specific Layer 2 frames on the segment the router is connected to. A successful exploit could allow the attacker to cause a queue wedge on the interface, resulting in a DoS condition.","severity":{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0036,"percentile":0.30237,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-399","CWE-400"],"published":"2021-09-23T02:31:07Z","modified":"2026-06-17T03:32:11Z","products":[{"vendor":"cisco","product":"cisco ios xe software"},{"vendor":"cisco","product":"ios_xe"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-quewedge-69BsHUBW","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-1621"},{"url":"https://github.com/advisories/GHSA-7pgq-9248-43gw"}],"sources":{"cve":[{"id":"CVE-2021-1621","title":"Cisco IOS XE Software Interface Queue Wedge Denial of Service Vulnerability","description":"A vulnerability in the Layer 2 punt code of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a queue wedge on an interface that receives specific Layer 2 frames, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of certain Layer 2 frames. An attacker could exploit this vulnerability by sending specific Layer 2 frames on the segment the router is connected to. A successful exploit could allow the attacker to cause a queue wedge on the interface, resulting in a DoS condition.","status":"published","published":"2021-09-23T02:31:07.087Z","modified":"2024-11-07T21:51:22.094Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-399"],"updated_at":"2026-11-02T14:33:08.811269Z"}],"euvd":[{"id":"EUVD-2021-7088","description":"A vulnerability in the Layer 2 punt code of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a queue wedge on an interface that receives specific Layer 2 frames, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of certain Layer 2 frames. An attacker could exploit this vulnerability by sending specific Layer 2 frames on the segment the router is connected to. A successful exploit could allow the attacker to cause a queue wedge on the interface, resulting in a DoS condition.","status":"published","published":"2021-09-23T02:31:07Z","modified":"2024-11-07T21:51:22Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T00:05:07.279991Z"}],"ghsa":[{"id":"GHSA-7pgq-9248-43gw","title":"A vulnerability in the Layer 2 punt code of Cisco IOS XE Software could allow an unauthenticated,...","description":"A vulnerability in the Layer 2 punt code of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a queue wedge on an interface that receives specific Layer 2 frames, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of certain Layer 2 frames. An attacker could exploit this vulnerability by sending specific Layer 2 frames on the segment the router is connected to. A successful exploit could allow the attacker to cause a queue wedge on the interface, resulting in a DoS condition.","status":"published","published":"2022-05-24T19:15:39Z","modified":"2023-01-30T05:02:28Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:46:38.51672Z"}],"nvd":[{"id":"CVE-2021-1621","description":"A vulnerability in the Layer 2 punt code of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a queue wedge on an interface that receives specific Layer 2 frames, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of certain Layer 2 frames. An attacker could exploit this vulnerability by sending specific Layer 2 frames on the segment the router is connected to. A successful exploit could allow the attacker to cause a queue wedge on the interface, resulting in a DoS condition.","status":"published","published":"2021-09-23T03:15:13.21Z","modified":"2026-06-17T03:32:11.247Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":3.3,"vector":"AV:A/AC:L/Au:N/C:N/I:N/A:P","level":"low","assessor":"primary"}],"cwes":["CWE-399"],"updated_at":"2026-11-02T14:06:58.933037Z"}]}}